In keeping with the missions of NIMH and NICHD, the proposed project offers to test innovative models of poverty-related risk and RCT early intervention targeting key health and mental health outcomes among low-income, ethnic minority youth. Overall, this application aims to advance our understanding of youths' trajectories of internalizing behavior and health risk across a salient life course transition (including 8th through 10th grade). Because the average age of onset for affective disorders, and the initiation of a broader array of health risk behaviors occurs in early adolescence, we plan to focus our efforts in predicting youths' health-risk behaviors and internalizing problems. Scientifically and clinically significant features of this project include an the opportunity to tet the role of key neurocognitive mechanisms that may alternately lead some youth to be at lower risk for these negative health and mental health sequelae, while other youth may face greater risk. Framed in this way, the proposed research strives to identify levers for policies and programs devoted to improving the health of adolescents in low-income communities. The specific aims of this application include the following. First, the proposed investigation will examine the long-term impact of the Chicago School Readiness Project (CSRP), a randomized controlled trial (RCT) of a preschool intervention designed to foster low-income preschoolers' self-regulation and mental health (#R01HD046160; n = 602). Treatment-induced gains in specific domains of self-regulation including emotion regulation (ER) and executive function (EF) are hypothesized to set youth on positive developmental trajectories into adolescence. The project's second aim is to test ways that youths' trajectories of health and mental health problems may be significantly jeopardized by a range of poverty-related risk factors, defined in terms of type of risk, the timing of risk exposure, and turbulence (i.e., volatility in risk). Analses will also test whether those key neurocognitive mechanisms of ER and EF mediate the impact of poverty and early intervention on individuals' internalizing and health risk, and whether these impacts are moderated by race/ethnicity, gender, and early regulatory profiles. Statistical approaches will include measurement modeling and advanced techniques that help to strengthen causal claims and to understand development over time.